Outline

Introduction: The small intestine is highly immunogenic and there is rising evidence that recurrent ACR episodes may trigger chronic rejection, having influence on the long term outcome. In previous studies, we established an experimental model to analyze the recovery and regeneration process after acute rejection. Infliximab is established in therapy of inflammatory bowel diseases, and it has been reported as successful rescue therapy for resistant rejection after small bowel transplantation. This study evaluated the effects of additional infliximab application during rescue therapy with tacrolimus basic immunosuppression to reveal mechanistical causes of this phenomenon.

Materials and methods: Orthotopic allogeneic intestinal transplantation was performed in rats. Immunosuppression with Tacrolimus 2mg/kg/day was started on POD1 (group 1/continuous immunosuppression) or POD7 after manifestation of acute rejection. Animals were sacrificed on POD7 (group 2/acute rejection, no treatment), POD14 (group 3/immunosuppression) and POD21 (group 4/immunosuppression) during the recovery process. Additional infliximab treatment was administered on POD7 conjointly with tacrolimus. Animals were sacrified on POD14 (group 5/immunosuppression) or POD21 (group 6/immunosuppression).